/*
 This source file is part of the Swift.org open source project

 Copyright (c) 2021-2024 Apple Inc. and the Swift project authors
 Licensed under Apache License v2.0 with Runtime Library Exception

 See https://swift.org/LICENSE.txt for license information
 See https://swift.org/CONTRIBUTORS.txt for Swift project authors
*/

import Foundation
import ArgumentParser

extension Docc.ProcessArchive {
    /// Emits a statically hostable website from a DocC Archive.
    struct TransformForStaticHosting: AsyncParsableCommand {
        
        static var configuration = CommandConfiguration(
            commandName: "transform-for-static-hosting",
            abstract: "Transform an existing DocC Archive into one that supports a static hosting environment.")
        
        @OptionGroup()
        var documentationArchive: DocCArchiveOption
        
        /// A user-provided location where the archive output will be put
        @Option(
            name: [.customLong("output-path")],
            help: ArgumentHelp(
                           "The location where docc writes the transformed archive.",
                           discussion: "If no output-path is provided, docc will perform an in-place transformation of the provided DocC Archive."
                       ),
            transform: URL.init(fileURLWithPath:)
        )
        var outputURL: URL?
        
        /// A user-provided relative path to be used in the archived output
        @Option(
            name: [.customLong("hosting-base-path")],
            help: ArgumentHelp(
                            "The base path your documentation website will be hosted at.",
                            discussion: "For example, to deploy your site to 'example.com/my_name/my_project/documentation' instead of 'example.com/documentation', pass '/my_name/my_project' as the base path.")
        )
        var hostingBasePath: String?
        
        /// The user-provided path to an HTML documentation template.
        @OptionGroup()
        var templateOption: TemplateOption

        mutating func validate() throws {
            if let templateURL = templateOption.templateURL {
                let indexTemplate = templateURL.appendingPathComponent(HTMLTemplate.templateFileName.rawValue)
                if !FileManager.default.fileExists(atPath: indexTemplate.path) {
                    throw TemplateOption.invalidHTMLTemplateError(
                        path: templateURL.path,
                        expectedFile: HTMLTemplate.templateFileName.rawValue
                    )
                }
            } else {
                throw TemplateOption.missingHTMLTemplateError(
                    path: templateOption.defaultTemplateURL.path
                )
            }
        }
        
        func run() async throws {
            let action = try TransformForStaticHostingAction(fromCommand: self)
            try await action.performAndHandleResult()
        }
    }
}

